DXOMark has just published the results for the Nikon Z7 II and compared them with the Canon EOS R5 and the Sony A7R IV, which are all fine cameras with excellent image quality.
Most readers will be interested in the dynamic range. However, as that is reported at the measured ISO it can be difficult to decipher from the graphs what the DR is at the manufacturer settings – they are after all what you set on the camera. It’s difficult to see at the lower ISOs, especally where manufacturer’s use extended low ISO settings that are in effect the same as the lowest native base setting.
As a visual aid, therefore, I’ve used DXOMark data at the manufacturer’s settings to make direct comparison a little easier to see. I’ve highlighted the Canon EOS R5 in this graph against the Nikon Z7 II and Sony A7R IV.
One important take away here is that if you’re using the Canon EOS R5, you may as well use ISO 400 instead of ISO 200. And although the Nikon Z7 II appears to have an advantage at ISO 64 (shown on the DXOMark site), you’ll see from the graph above that’s not strictly the case. The Sony is on a practically on a par with the Nikon at ISO 64 when set to ISO 50 and ISO 100, which are effectively the same sensitivity. At ISO 100, the Sony even offers slightly better DR than the Nikon Z 7 II (when set to ISO 100).
Admittedly the Canon EOS R5 has slightly lower DR at ISO 50 than the Nikon Z7 II at ISO 64, however as the Canon has same sensitivity/response at ISO 50 and ISO 100 (the same strategy as the Sony), you may as well set ISO 100 and have practically the same DR as the Nikon Z7 II at ISO 64. There’s no real benefit to setting ISO 50 on the Canon EOS R5. At ISO 100, the Nikon even has lower DR than the Canon, and that’s true again ISO 400.
I might write another article here about the Low-light ISO score, as it seems to be the least understood metric. From various comments around the internet many don’t seem to realise that the ISO value is measured taking dynamic range and colour depth into account. Thus, if a camera doesn’t perform well in dynamic range and colour at high ISOs, then the low light score’s ISO value will be lower. That’s why the stacked sensors don’t achieve quite the same high ISO values as the conventional BSI types (though to be fair they’re close), which in turn are better than the typical front-side illuminated models. Leave a comment below if it’s of interest.